1. Technology Field
The present invention relates to a method of raster-scan search for OSD (On-Screen Display, hereinafter abbreviated as “OSD”) and to a system using the same, and more particularly to a method of raster-scan search for multi-region OSD and to a system using the same.
2. Description of Related Art
Currently, multimedia electronic devices such as portable multimedia players (PMP) and televisions (TV) are generally equipped with OSD capabilities. Referring to FIG. 1, FIG. 1 is an exemplary display for illustrating the OSD and a main image on a screen of a multimedia electronic device. Referring to FIG. 1, the main image is usually displayed on a background of a screen 110 when multi-region OSD (such as a region A 130, a region B 132, a region C 134, a region D 136 and a region E 138) are launched at any time in response to a request from a user. The main image could be, for example, a sports event, a movie, or an advertisement video. Besides, the region A 130, the region B 132, the region C 134, the region D 136 and the region E 138 may not be launched simultaneously and may contain different texts, graphics, or even video.
Usually, the OSD or the multi-region OSD are displayed on top of the main image, but, in some cases, the multi-region OSD may be displayed transparently along with the main image on the background if an alpha-blending technique is applied in the screen of the multimedia electronic device. However, if there are randomized sequence of the multi-region OSD to be displayed on the screen, four OSD regions on one layer to be displayed on the screen, or an unlimited number of OSD regions on multilayer to be displayed on the screen, dynamically determining blending positions of the multi-region OSD and accessing OSD data of the multi-region OSD in time would require massive memory bandwidth, high speed processing capability, and consequently consumes a large amount of power.